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<?xml version='1.0'?> <!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
<refentry id="sd_device_get_syspath"
xmlns:xi="http://www.w3.org/2001/XInclude">
<refentryinfo>
<title>sd_device_get_syspath</title>
<productname>systemd</productname>
</refentryinfo>
<refmeta>
<refentrytitle>sd_device_get_syspath</refentrytitle>
<manvolnum>3</manvolnum>
</refmeta>
<refnamediv>
<refname>sd_device_get_syspath</refname>
<refname>sd_device_get_devpath</refname>
<refname>sd_device_get_sysname</refname>
<refname>sd_device_get_sysnum</refname>
<refname>sd_device_get_subsystem</refname>
<refname>sd_device_get_driver_subsystem</refname>
<refname>sd_device_get_devtype</refname>
<refname>sd_device_get_devname</refname>
<refname>sd_device_get_devnum</refname>
<refname>sd_device_get_ifindex</refname>
<refname>sd_device_get_driver</refname>
<refname>sd_device_get_diskseq</refname>
<refname>sd_device_get_device_id</refname>
<refpurpose>Returns various fields of device objects</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcsynopsisinfo>#include <systemd/sd-device.h></funcsynopsisinfo>
<funcprototype>
<funcdef>int <function>sd_device_get_syspath</function></funcdef>
<paramdef>sd_device *<parameter>device</parameter></paramdef>
<paramdef>const char **<parameter>ret</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_device_get_devpath</function></funcdef>
<paramdef>sd_device *<parameter>device</parameter></paramdef>
<paramdef>const char **<parameter>ret</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_device_get_sysname</function></funcdef>
<paramdef>sd_device *<parameter>device</parameter></paramdef>
<paramdef>const char **<parameter>ret</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_device_get_sysnum</function></funcdef>
<paramdef>sd_device *<parameter>device</parameter></paramdef>
<paramdef>const char **<parameter>ret</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_device_get_subsystem</function></funcdef>
<paramdef>sd_device *<parameter>device</parameter></paramdef>
<paramdef>const char **<parameter>ret</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_device_get_driver_subsystem</function></funcdef>
<paramdef>sd_device *<parameter>device</parameter></paramdef>
<paramdef>const char **<parameter>ret</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_device_get_devtype</function></funcdef>
<paramdef>sd_device *<parameter>device</parameter></paramdef>
<paramdef>const char **<parameter>ret</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_device_get_devname</function></funcdef>
<paramdef>sd_device *<parameter>device</parameter></paramdef>
<paramdef>const char **<parameter>ret</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_device_get_devnum</function></funcdef>
<paramdef>sd_device *<parameter>device</parameter></paramdef>
<paramdef>dev_t *<parameter>ret</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_device_get_ifindex</function></funcdef>
<paramdef>sd_device *<parameter>device</parameter></paramdef>
<paramdef>int *<parameter>ret</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_device_get_driver</function></funcdef>
<paramdef>sd_device *<parameter>device</parameter></paramdef>
<paramdef>const char **<parameter>ret</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_device_get_diskseq</function></funcdef>
<paramdef>sd_device *<parameter>device</parameter></paramdef>
<paramdef>uint64_t *<parameter>ret</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_device_get_device_id</function></funcdef>
<paramdef>sd_device *<parameter>device</parameter></paramdef>
<paramdef>const char **<parameter>ret</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para><function>sd_device_get_syspath()</function> returns the sysfs path of the specified device record,
including the <filename>/sys</filename> prefix. Example: <filename>/sys/devices/virtual/tty/tty7</filename></para>
<para><function>sd_device_get_devpath()</function> returns the sysfs path of the specified device record,
excluding the <filename>/sys</filename> prefix. Example: <filename>/devices/virtual/tty/tty7</filename></para>
<para><function>sd_device_get_sysname()</function> returns the sysfs name of the specified device record,
i.e. the last component of the sysfs path. Example: <literal>tty7</literal> for the device
<filename>/sys/devices/virtual/tty/tty7</filename></para>
<para><function>sd_device_get_sysnum()</function> returns the sysfs device number of the specified device
record, i.e. the numeric suffix of the last component of the sysfs path. Example: <literal>7</literal>
for the device <filename>/sys/devices/virtual/tty/tty7</filename></para>
<para><function>sd_device_get_subsystem()</function> returns the kernel subsystem of the specified device
record. This is a short string fitting into a filename, and thus does not contain a slash and cannot be
empty. Example: <literal>tty</literal>, <literal>block</literal> or <literal>net</literal>.</para>
<para><function>sd_device_get_driver_subsystem()</function> returns the connected bus type of the devices
loaded by the specified driver device record. For example, when <literal>iwlwifi</literal> driver device
is specified, which is used by the wireless network interfaces connected to PCI bus, this function returns
<literal>pci</literal>. This function only succeeds when <function>sd_device_get_subsystem()</function>
returns <literal>drivers</literal>. Example: <literal>pci</literal>, <literal>i2c</literal>, or
<literal>hid</literal>.</para>
<para><function>sd_device_get_devtype()</function> returns the device type of the specified device
record, if the subsystem manages multiple types of devices. Example: for devices of the
<literal>block</literal> subsystem this can be <literal>disk</literal> or <literal>partition</literal>
</para>
<para><function>sd_device_get_devname()</function> returns the device node path of the specified device
record if the device has a device node. Example: for <filename>/sys/devices/virtual/tty/tty7</filename>
the string <filename>/dev/tty7</filename> is typically returned.</para>
<para><function>sd_device_get_devnum()</function> returns the device node major/minor
(i.e. <type>dev_t</type>) of the specified device record if the device has a device node (i.e. the one
returned by <function>sd_device_get_devname()</function>). For devices belonging to the
<literal>block</literal> subsystem this refers to a block device node, in all other cases to a character
device node. Example: for the <filename>/sys/devices/virtual/tty/tty7</filename> device this typically
returns the device number with major/minor <literal>4:7</literal>.</para>
<para><function>sd_device_get_ifindex()</function> returns the network interface index of the specified
device record, if the device encapsulates a network interface device, i.e. belongs to the
<literal>net</literal> subsystem. Example: the <literal>lo</literal> interface typically has interface
index 1.</para>
<para><function>sd_device_get_driver()</function> returns the kernel driver name attached to the
device. Note that the driver field is set on the devices consumed by the driver, not on the device
created by it. Example: a PCI device <filename>/sys/bus/pci/devices/0000:00:1f.6</filename> might be
attached to a driver <literal>e1000e</literal>.</para>
<para><function>sd_device_get_diskseq()</function> returns the kernel disk sequence number of the block
device. This number monotonically increases whenever a backing medium of a block device changes without
the device name changing, and is relevant for block devices encapsulating devices with changing media
(e.g. floppy or CD-ROM), or loopback block devices. Only defined for block devices, i.e. those of
subsystem <literal>block</literal>.</para>
<para><function>sd_device_get_device_id()</function> returns the short string that identifies the device
record. When the device ID obtained by the function for a specified device record is passed to
<function>sd_device_new_from_device_id()</function>, a new instance of the same device record will be
gained. When a block or character device is specified, which has corresponding device node, this returns
<literal>b</literal> or <literal>c</literal>, respectively, followed by the device node major and minor
numbers separated with a colon. Example: <literal>b259:1</literal> or <literal>c10:121</literal>. When a
network interface device is specified, this returns <literal>n</literal> followed by the interface index,
which can be obtained by <function>sd_device_get_ifindex()</function>. Example: <literal>n1</literal>.
When a device in the <literal>driver</literal> subsystem is specified, this returns
<literal>+drivers:</literal> followed by its driver subsystem and sysfs name separated with a colon.
Example: <literal>+drivers:pci:iwlwifi</literal> for a driver device record whose driver subsystem is
<literal>pci</literal> and sysfs name is <literal>iwlwifi</literal>,
When another type of device is specified, this function returns <literal>+</literal> followed by its
subsystem and sysfs name separated with a colon. Example: <literal>+acpi:ACPI0003:00</literal>,
<literal>+input:input16</literal>, or <literal>+pci:0000:00:1f.6</literal>.</para>
</refsect1>
<refsect1>
<title>Return Value</title>
<para>On success, these calls return 0 or a positive integer. On failure, they return a negative
errno-style error code.</para>
<refsect2>
<title>Errors</title>
<para>Returned errors may indicate the following problems:</para>
<variablelist>
<varlistentry>
<term><constant>-EINVAL</constant></term>
<listitem><para>A specified parameter is invalid.</para>
<xi:include href="version-info.xml" xpointer="v251"/></listitem>
</varlistentry>
<varlistentry>
<term><constant>-ENOENT</constant></term>
<listitem><para>The requested field is not present in the device record.</para>
<xi:include href="version-info.xml" xpointer="v251"/></listitem>
</varlistentry>
</variablelist>
</refsect2>
</refsect1>
<xi:include href="libsystemd-pkgconfig.xml" />
<refsect1>
<title>History</title>
<para><function>sd_device_get_syspath()</function>,
<function>sd_device_get_devpath()</function>,
<function>sd_device_get_sysname()</function>,
<function>sd_device_get_sysnum()</function>,
<function>sd_device_get_subsystem()</function>,
<function>sd_device_get_devtype()</function>,
<function>sd_device_get_devname()</function>,
<function>sd_device_get_devnum()</function>,
<function>sd_device_get_ifindex()</function>,
<function>sd_device_get_driver()</function>, and
<function>sd_device_get_diskseq()</function> were added in version 251.</para>
<para><function>sd_device_get_driver_subsystem()</function> and
<function>sd_device_get_device_id()</function> were added in version 257.</para>
</refsect1>
<refsect1>
<title>See Also</title>
<para><simplelist type="inline">
<member><citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
<member><citerefentry><refentrytitle>sd-device</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
</simplelist></para>
</refsect1>
</refentry>
|
